It's a different world when it comes to watching entertainment. Where once there was a choice between an antenna or cable TV, now we have small gadgets that bring us television, movies, and entertainment on demand.

Want to marathon every episode of the original "Star Trek" at 3 a.m. on a Sunday morning? You got it. You just need the right device to help bring it to your living room.

Let's take a stroll through the big shakers: Apple TV, Amazon Fire, Google Chromecast, and Roku. They're competitors, but they have a lot of overlaps, as well as some big areas of difference.

The one you choose will depend on your viewing habits, brand loyalty, and how you prefer to consume your streaming media.

APPLE TV

The latest version of the Apple TV box arrived in 2015. It comes stocked with a slick user interface, Siri-enabled voice search, a sleek remote control, and integration with Apple's app store.

The gadget is made to appeal to iPhone and Mac-toting Apple fans who rely on iTunes to stay caught up on their favorite television shows and movies. The Apple TV comes in two flavors, which are separated by the amount of built-in storage space.

The 32 GB version of the latest Apple TV costs $149 and will handle the needs of most streaming fans. If you plan to go nuts downloading apps and games, then the $199 option with 64 GB of storage is worth the upgrade.

Should you buy an Apple TV? If you are already a heavy user of iTunes and have invested in a lot of purchases through Apple’s media store, then this makes sense.

Think of the Apple TV as a luxury gadget. It’s one of the most expensive streaming boxes on the market. If money is a consideration, then you can check out one of the more budget-friendly options from the competition.